The root ᴹ√EREK appeared in The Etymologies of the 1930s with the gloss “thorn” and derivatives meaning “prick” or “holly” in both Quenya and Noldorin (Ety/ERÉK). Elsewhere in the document it appeared in its unaugmented form ᴹ√REK (EtyAC/REK). It was the basis of the two names Ilk. Region and N. Eregion “Hollin”. The continued appearance of these names in the legendarium indicates the continued validity of these roots.
Primitive elvish
k(e)rek
root. *spit [noun]
rek
root. recover, get out/away, save from ruin/peril/loss
A root glossed “recover, get out/away, save from ruin/peril/loss” in notes on the words from The Lord of the Rings, serving as an explanation for S. edraith “rescue, saving” (PE17/38).